Electric vehicle

ABSTRACT

An electric vehicle capable of efficiently and reliably cooling a power converter disposed inside an exterior. The electric vehicle includes a frame extending in a longitudinal direction of the electric vehicle, a power converter being long in the longitudinal direction of the electric vehicle along the frame, and an exterior extending in the longitudinal direction to cover the frame and the power converter, the exterior defining a cooling air path between the power converter to allow cooling air to flow the cooling air path. The power converter includes a plurality of heat radiation fins extending in the longitudinal direction of the electric vehicle in the cooling air path, the heat radiation fins protruding toward an inner surface of the exterior. Some of the heat radiation fins are closer to the inner surface of the exterior than the other heat radiation fins.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of Japanese PatentApplication No. 2015-210400, filed on Oct. 27, 2015, the entire contentsof which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an electric vehicle.

Description of the Related Art

There is known a fuel cell motorcycle in which a power converter, orspecifically a DC-DC converter, is connected between a fuel cell and anelectric motor, and output of the electric motor is transmitted to arear wheel.

This conventional fuel cell motorcycle includes a DC-DC converterdisposed on any one of right and left sides of a rear wheel (e.g. referto Patent Document 1 (Japanese Patent Laid-Open No. 2002-187587)).

SUMMARY OF THE INVENTION

The conventional fuel cell motorcycle includes the DC-DC converterprovided along with a frame inside an exterior with which the frame iscovered, and the fuel cell, the DC-DC converter, and a motor controllerare cooled by travelling wind passing through the inside of the exteriorduring travelling.

Unfortunately, the conventional fuel cell motorcycle only allows heatradiation fins provided in the DC-DC converter to be exposed totravelling wind passing through the inside of the exterior. Such acooling structure of the DC-DC converter cannot allow a sufficientamount of air to flow between the heat radiation fins in which airresistance increases as compared with the periphery of the DC-DCconverter, and contrarily allows air to detour in the periphery of theDC-DC converter so as to avoid the heat radiation fins, therebydeteriorating in cooling efficiency.

To solve the problems described above, it is an object of the presentinvention to provide an electric vehicle capable of efficiently andreliably cooling a power converter disposed inside an exterior.

To achieve the above object, an aspect of the present invention providesan electric vehicle including a frame extending in a longitudinaldirection of the electric vehicle, a power converter being long in thelongitudinal direction of the electric vehicle along the frame, and anexterior extending in the longitudinal direction to cover the frame andthe power converter, the exterior defining a cooling air path betweenwith the power converter to allow cooling air to flow the cooling airpath. The power converter includes a plurality of heat radiation finsextending in the longitudinal direction of the electric vehicle in thecooling air path, the heat radiation fins projecting toward an innersurface of the exterior. Some of the heat radiation fins are closer tothe inner surface of the exterior than the other heat radiation fins.

In preferred embodiments of the above aspect, the following modes may beprovided.

It may be desired that the some of the heat radiation fins include aheat radiation fin disposed at an uppermost portion, and a heatradiation fin disposed on a lowermost portion.

It may be desired that the exterior includes a recessed portion thatpartially reduces a cross-sectional area of the cooling air path, andeach heat radiation fins have a projection length reduced along therecessed portion.

This electric vehicle is capable of efficiently and reliably cooling apower converter disposed inside an exterior.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side view of an electric vehicle according to anembodiment of the present invention;

FIG. 2 is a left side view of the electric vehicle according to theembodiment of the present invention, with its exteriors being detached;

FIG. 3 is a perspective view of the electric vehicle according to theembodiment of the present invention, with its exteriors being detached;

FIG. 4 is a perspective view of a cooling structure of a power converterof the electric vehicle according to the embodiment of the presentinvention;

FIG. 5 is a perspective view of the cooling structure of the powerconverter of the electric vehicle according to the embodiment of thepresent invention;

FIG. 6 is a plan view of the cooling structure of the power converter ofthe electric vehicle according to the embodiment of the presentinvention;

FIG. 7 is a right side view of the cooling structure of the powerconverter of the electric vehicle according to the embodiment of thepresent invention;

FIG. 8 is a front view of the cooling structure of the power converterof the electric vehicle according to the embodiment of the presentinvention;

FIG. 9 is a rear view of the cooling structure of the power converter ofthe electric vehicle according to the embodiment of the presentinvention;

FIG. 10 is a sectional view of the cooling structure of the powerconverter of the electric vehicle according to the embodiment of thepresent invention; and

FIG. 11 is a sectional view of the cooling structure of the powerconverter of the electric vehicle according to the embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, an embodiment of an electric vehicle according to thepresent invention will be described with reference to FIGS. 1 to 11.

FIG. 1 is a left side view of the electric vehicle according to anembodiment of the present invention.

FIG. 2 is a left side view of the electric vehicle according to anembodiment of the present invention, with its exteriors, for example,covers and a seat being detached.

FIG. 3 is a perspective view of the electric vehicle according to anembodiment of the present invention, with its exteriors, for example,covers and a seat being detached.

Note that expressions of front-and-rear, up-and-down, and left-and-rightin the present embodiment are based on reference to a rider onboard anelectric vehicle 1. In FIGS. 1 to 3, a solid line arrow F representsforward of the electric vehicle 1, and a solid line arrow R representsreward of the electric vehicle 1.

As shown in FIGS. 1 to 3, the electric vehicle 1 according to thepresent embodiment travels by being driven by an electric motor 3powered by a fuel cell 2. The electric vehicle 1 is a motorcycle ofmotor-scooter type, and also a fuel cell powered bicycle traveling bythe power of the fuel cell 2. The electric vehicle 1 may also be atricycle. It may be a type of vehicle that travels by being driven bythe electric motor 3 that is powered by a rechargeable battery (notshown) in place of the fuel cell 2.

The electric vehicle 1 includes a vehicle body 5 extending forward andrearward, a front wheel 6 as a steered wheel, a steering mechanism 7supporting the front wheel 6 in a steerable manner, a rear wheel 8 as adriving wheel, a swing arm 9 supporting the rear wheel 8 so as to beswingable in the up and down direction, and the electric motor 3 whichgenerates driving power of the rear wheel 8.

The vehicle body 5 includes a frame 11 extending forward and rearward ofthe vehicle, an exterior 12 covering the frame 11, and a seat 13disposed above a rear half part of the frame 11.

Further, the vehicle body 5 includes a fuel cell 2, a fuel tank 15configured to store high pressure gas of hydrogen as a fuel to be usedfor power generation in the fuel cell 2, a rechargeable battery 16configured to supplement power of the fuel cell 2, a power managementapparatus 17 configured to adjust output voltage of the fuel cell 2 andcontrol power distribution between the fuel cell 2 and the rechargeablebattery 16, an inverter 18 configured to convert DC power outputted bythe power management apparatus 17 into three-phase AC power and outputsit to the electric motor 3 to operate the electric motor 3, and avehicle controller 19 configured to comprehensively control thosementioned before.

A power train of the electric vehicle 1 includes the fuel cell 2 and therechargeable battery 16, is a system which appropriately utilizes powerof each power supply depending on travelling conditions of the vehicle,power generation conditions of the fuel cell 2, and power storageconditions of the rechargeable battery 16. The electric vehicle 1generates regenerative power at the electric motor 3 duringdeceleration. The rechargeable battery 16 and the fuel cell 2, which arepower sources of the vehicle, are connected in parallel to the inverter18 and supply power to the electric motor 3. The rechargeable battery 16stores regenerative power generated at the electric motor 3 when theelectric vehicle 1 decelerates, and power generated by the fuel cell 2.

The frame 11 is made up of a plurality of steel hollow pipes combinedinto a single body. The frame 11 includes a head pipe 21 disposed abovethe front end of the frame 11, an upper down-frame 22 extending from acentral part of the head pipe 21 in a rearwardly and downwardly inclinedmanner, a lower down-frame 23 disposed below the head pipe 21 andextending in a rearwardly and downwardly inclined manner, a pair of leftand right lower frames 24, a pair of left and right upper frames 25, apivot shaft 26, an upper bridge frame 27, a lower bridge frame 28, aguard frame 29, and a mounted-instrument protection frame 30.

The head pipe 21 supports the steering mechanism 7 so as to besteerable, that is, to be swingable in the left and right direction ofthe electric vehicle 1.

The pair of left and right lower frames 24 are disposed in the left andthe right of the lower down-frame 23 and connected to a lower part ofthe head pipe 21. The pair of left and right lower frames 24 eachinclude a front-side inclined portion extending from a connected portionwith the head pipe 21 substantially in parallel along the lowerdown-frame 23 and in a rearwardly and downwardly inclined manner, afront-side curved portion curved rearwardly at a lower end of thefront-side inclined portion, and a straight portion extendingsubstantially horizontally from a rear end of the front-side curvedportion toward rearward of the vehicle body 5 in a linear manner untilreaching a central portion of the vehicle body 5, that is, a centralportion in the front and rear direction of the electric vehicle 1. Thepair of left and right lower frames 24 each include a rear-side curvedportion curved toward rearward and upward from a rear end part of thestraight portion, a rear-side inclined portion extending from an upperend part of the rear-side curved portion in a rearwardly and upwardlyinclined manner, and an upper and lower frame joining part connectingthe rear-side inclined portion to the upper frame 25. A spacing betweenthe left and right lower frames 24 is wider than that between the leftand right upper frames 25.

A near-head-pipe bridge frame 34 is constructed between upper parts ofthe left and right lower frames 24. The near-head-pipe bridge frame 34extends in a linear manner substantially in the left and right directionof the electric vehicle 1. Each of the left and right lower frames 24includes a foot rest bracket 31 a. The foot rest bracket 31 a supports afoot board 31, which is disposed on the outer side of the front-sidecurved portion, from below. A rider can lay its foot on the foot board31.

The lower frame 24 being disposed on the left side of the vehicle body 5includes a side stand bracket (not shown). The side stand bracket (notshown) is provided with a side stand (not shown) configured to make theelectric vehicle 1 stand by itself in a leftwardly inclined manner. Theside stand swings between an erected position for making the electricvehicle 1 stand by itself, and a retracted position for making it stayalong the vehicle body 5 so as not to impede travelling.

The pair of left and right upper frames 25 are connected to a centralpart in the up-and-down direction of the front-side inclined portion ofthe lower frame 24 in a front half part of the vehicle body 5. The pairof left and right upper frames 25 each include, horizontal portionsextending from a connected portion with the front-side inclined portionof the lower frame 24 toward rearward of the vehicle body 5 in asubstantially horizontal manner, and rear end parts being rear ends ofthe horizontal portions of the pair of left and right upper frames 25,the rear end parts being significantly inclined rearwardly and upwardlyin the rear half part of the vehicle body 5 and above the rear wheel 8,the rear end parts curved inwardly in the left and right direction ofthe vehicle body 5 to come close to each other to an extent of aboutthickness (width size) of the rear wheel 8.

The pivot shaft 26 is constructed between the left and right upperframes 25 in the rear half part of the vehicle body 5. The pivot shaft26 is constructed between a pair of left and right brackets 26 a. Eachof the brackets 26 a is located below the upper frame 25 and in the rearof a merging portion (upper and down frame joining part) between theupper frame 25 and the lower frame 24. Each of the brackets 26 a isconnected to the horizontal portion of the upper frame 25, and to therear-side inclined portion of the lower frame 24.

The upper bridge frame 27 is constructed between the front end parts ofthe left and right upper frames 25. The upper bridge frame 27 extendssubstantially linearly in the left and right direction of the vehiclebetween the left and right upper frames 25 to interconnect the left andright upper frames 25.

The lower bridge frame 28 is constructed between the front-side curvedportions of the left and right lower frames 24. The lower bridge frame28 extends substantially linearly in the left and right direction of thevehicle between the left and right lower frames 24 to interconnect theleft and right lower frames 24.

The guard frame 29 is constructed between the rear-side curved portionsof the left and right lower frames 24. The guard frame 29 extendsrearwardly and downwardly from a connected portion with the left andright lower frames 24, and extends into a rearwardly declined U-shape soas to enlarge the internal space of the frame 11. The guard frame 29 isprovided with a center stand 33 configured to make the electric vehicle1 stand by itself in an upright state. The center stand 33 swingsbetween an erected position for making the electric vehicle 1 stand byitself, and a retracted position for making it stay along the vehiclebody 5 so as not to impede travelling.

The upper down-frame 22 is constructed between the head pipe 21 and theupper bridge frame 27.

The lower down-frame 23 includes an upper end part connected to acentral part in the left and right direction of the electric vehicle 1of a near-head-pipe bridge frame 34 constructed between the left andright lower frames 24, and a lower end part connected to a central partin the left and right direction of the electric vehicle 1 of the lowerbridge frame 28.

The mounted-instrument protection frame 30 is provided above the rearhalf part of the upper frame 25. The mounted-instrument protection frame30 supports and secures the fuel cell 2 to the electric vehicle 1. Apart of the mounted-instrument protection frame 30 can be attached anddetached to and from the upper frame 25.

The seat 13 extends forward and rearward covering an upper section ofthe rear half part of the frame 11. The seat 13 is of a tandem type andincludes a front half part 13 a on which the rider is to be seated, arear half part 13 b on which a passenger is to be seated, and aninclined part 13c between the front half part 13 a and the rear halfpart 13 b.

Here, a space surrounded by the left and right upper frames 25 and theleft and right lower frames 24 is referred to as a center tunnel region35. A space surrounded by the rear half part of the upper frame 25,exterior 12, and the seat 13 as an instrument mounting region 36. Aspace in the rear of the center tunnel region 35 and below theinstrument mounting region 36 as a tire house region 37.

The center tunnel region 35 accommodates the fuel tank 15. In theelectric vehicle 1 of a motor-scooter type according to the presentembodiment, the center tunnel region 35 is disposed along the front andrear direction of the electric vehicle 1 and between left and right footboards 31 on which the rider places its foot, and rises higher than thefoot board 31 such that the foot resting region of the foot board 31 isdivided into left and right sections. In other words, the foot board 31,which serves as the foot resting region, is disposed in the left andright of the center tunnel region 35, and the fuel tank 15 is disposedbetween the left and right foot boards 31.

The instrument mounting region 36 accommodates the rechargeable battery16, the power management apparatus 17, and the fuel cell 2 in this orderfrom the front side of the vehicle body 5. The mounted-instrumentprotection frame 30 protects the front end part, the central part, therear end part, and a side part ranging from the central part to the rearend part of the instrument mounting region 36.

The mounted-instrument protection frame 30 surrounds the instrumentmounting region 36 and protects instruments to be mounted in theinstrument mounting region 36. The mounted-instrument protection frame30 includes a front protection frame 30 a disposed in the front end partof the instrument mounting region 36, the front protection frame 30 abeing constructed between the left and right upper frames 25 in anupwardly convex arch shape, a center protection frame 30 b disposed in acentral part of the instrument mounting region 36 and in the rear of amerging spot between the upper frame 25 and the lower frame 24, thecenter protection frame 30 b being constructed between the left andright upper frames 25 in an upwardly convex arch shape, a pair of leftand right rear protection frames 30 c disposed at a rear end part of theinstrument mounting region 36, the pair of left and right rearprotection frames 30 c being connected to a portion where each of theleft and right upper frames 25 is curved inwardly, the pair of left andright rear protection frames 30 c extending rearward and obliquelyupward from the curved portion, a pair of left and right side protectionframes 30 d extending rearward from each of the left and right of thecenter protection frame 30 b to be connected to the upper end parts ofthe rear protection frames 30 c , the pair of left and right sideprotection frames 30 d reaching the rear end part of the vehicle body 5,a bracket 30 e constructed between rear end parts of the left and rightside protection frames 30 d.

The left and right upper frames 25 are bent at a spot where the lowerends of the front protection frame 30 a are joined thereto, increase thespacing therebetween toward the rear of the electric vehicle 1. The leftand right upper frames 25 are bent at a spot where the lower ends of thecenter protection frame 30 b are joined thereto, and extend to the rearof the electric vehicle 1. Thus, the center protection frame 30 b has alarger width and a larger height than those of the front protectionframe 30 a. The rear protection frame 30 c and the pair of the left andright side protection frames 30 d are integrated.

The rear protection frame 30 c and the pair of left and right sideprotection frames 30 d are detachably interconnected to the centerprotection frame 30 b and the upper frames 25, thereby supporting thefuel cell 2.

A rear wheel 8 is disposed in the tire house region 37.

Between the instrument mounting region 36 and the tire house region 37,a rear fender 38 as a partition member for dividing respective regionsis provided.

The exterior 12 includes, a front leg-shield cover 41 covering a fronthalf part of the vehicle body 5, a front frame cover 42 disposed abovethe center of the vehicle body 5 and covering an upper section of theupper frame 25 such as the center tunnel region 35, and a frame cover 43disposed in a rear half part of the vehicle body 5 and covering a lowerportion of the seat 13.

The frame cover 43 along with the seat 13 surrounds the instrumentmounting region 36. The instrument mounting region 36 is a closed spacesurrounded by the seat 13, the frame cover 43, and the rear fender 38.The instrument mounting region 36 easily and securely controls flow ofair to the fuel cell 2 by means of a vent hole (not shown) provided inan appropriate area of the frame cover 43 or the rear fender 38, andalso easily and securely controls flow of air as a cooling wind to anapparatus, which needs to be cooled. The instrument mounting region 36allows air to enter from, for example, a joint of each cover (such asthe front frame cover 42, and a frame cover 43).

The steering mechanism 7 is disposed in a front section of the vehiclebody 5 and swings in the left and right direction centering on the headpipe 21 of the frame 11, thereby enabling steering of the front wheel 6.The steering mechanism 7 includes a handle 45 provided in a top part,and a pair of left and right front forks 46 interconnecting the handle45 and the front wheel 6, and the pair of left and right front forks 46extending in the up and down direction slightly inclined rearwardly. Theleft and right front forks 46 have a telescopic structure that can beelastically expanded and contracted. An axle (not shown) for rotatablysupporting the front wheel 6 is constructed between lower end parts ofthe left and right front forks 46. The front fender 47 is disposed abovethe front wheel 6. The front fender 47 is located between the left andright front forks 46, and secured to the front fork 46.

The front wheel 6 is a driven wheel that is rotatable about the axleconstructed between the lower end parts of the left and right frontforks 46.

The swing arm 9 swings in the up and down direction about the pivotshaft 26 as a rotational center extending in the left and rightdirection of the vehicle body 5. The swing arm 9 rotatably supports therear wheel 8 between a pair of arms extending in the front and reardirection on left and right sides of the vehicle body 5, respectively. Arear suspension 48 is constructed between the frame 11 and the swing arm9. The upper end part of the rear suspension 48 is swingably supportedat the rear end part of the upper frame 25. The lower end part of therear suspension 48 is swingably attached to the rear end part of theswing arm 9. The rear suspension 48 buffers the swinging of the swingarm 9.

The swing arm 9 accommodates a electric motor 3 rotationally driving therear wheel 8, and an inverter 18 converting DC power supplied from thefuel cell 2 into AC power to supply it to the electric motor 3.

The electric motor 3 rotationally drives the rear wheel 8 with powersupplied from the fuel cell 2 or the rechargeable battery 16, therebycausing the electric vehicle 1 to travel. The electric motor 3 isaccommodated in a rear part of the swing arm 9 and coaxially disposedwith the axle of the rear wheel 8. The electric motor 3 is integrallyassembled to the swing arm 9 to constitute a unit-swing-type swing arm.

The inverter 18 is accommodated in a front part of the swing arm 9, anddisposed between the pivot shaft 26 and the electric motor 3. Theinverter converts DC power outputted by the power management apparatus17 into three-phase AC power, and adjusts the rotational speed of theelectric motor 3 by altering the frequency of the AC power.

The rear wheel 8 is the driving wheel being supported by the axle (notshown) to which driving force is transferred from the electric motor 3.

The fuel cell 2 generates power by causing reaction between a fuel andan oxidizing agent. The fuel cell 2 is an air-cooled fuel cell systemgenerating power by using a high pressure gas, for example, hydrogen gasas the fuel, and oxygen in the air as the oxidizing agent, and is cooledby using air.

The fuel cell 2 is disposed on the rear half side of the instrumentmounting region 36. The fuel cell 2 is disposed below the seat 13 over arange from an inclined part between the front half part 13 a and rearhalf part 13 b to the rear half part 13 b. That is, in the side view ofthe vehicle, the fuel cell 2 is disposed between the rear half part 13 bof the seat 13, on which the passenger is to be seated, and the rearwheel 8 and the swing arm 9.

The fuel cell 2 has a cuboidal shape having a long side extending in thefront and rear direction of the vehicle body 5, and is disposed in theinstrument mounting region 36 in a posture in which its front face, inwhich the intake port 2 a is disposed, faces forward and obliquelydownward, and its back face, in which the exhaust port 2 b is disposed,faces rearward and obliquely upward. That is, the fuel cell 2 is securedto the frame 11 in a forward leaning posture in which its front side islocated lower than its rear side. The upper part of the fuel cell 2 issecured to a mounted instrument protection frame 30 and the lower partof the fuel cell 2 is secured to the upper frame 25.

The fuel cell 2 includes a plurality of flat modules interconnected fromthe front side toward the rear side. The fuel cell 2 includes a filter(not shown), an intake shutter (not shown), a fuel cell stack (notshown), a fan (not shown), and an exhaust shutter (not shown), which areinterconnected by being superposed on each other in a laminated state inorder from the front side. A fuel cell control unit (not shown) isprovided on the top face of the fuel cell 2.

The intake shutter includes an openable/closable intake port 2 a of air,and configured to control the amount of air introduced to the fuel cellstack by opening/closing the intake port 2 a. The intake shutterconfigured to constitute a circulation path for circulating air in thefuel cell 2 by closing the intake port 2 a. The exhaust shutter includesan openable/closable exhaust port 2 b of air and configured toconstitute the circulation path for circulating air in the fuel cell 2by closing the exhaust port 2 b. In other words, the fuel cell 2includes the openable/closable intake port 2 a in the front face, andthe openable/closable exhaust port 2 b in the back face, and configuredto cause air to be circulated in the fuel cell 2 by closing the intakeport 2 a and the exhaust port 2 b.

The fuel cell stack causes electrochemical reaction between oxygencontained in the air drawn through the intake port and hydrogen suppliedfrom the fuel tank 15 to generate power, and produces a wet excess gasafter generation.

The fan generates intake negative pressure for drawing air in theinstrument mounting region 36 from the intake port into the fuel cell 2,while drawing out the excess gas from the fuel cell stack and dischargesit from the exhaust port. The flow of air being caused by the fan isused for the power generation in the fuel cell stack, as well as for thecooling of the fuel cell 2.

An exhaust duct 52 is provided in the rear of the fuel cell 2. The fanof the fuel cell 2 draws out excess gas from the fuel cell stack anddischarges it to the exhaust duct 52. The front end part of the exhaustduct 52 is airtightly connected to a box, which is a frame body of theexhaust shutter, of the fuel cell 2. The exhaust duct 52 includes anexhaust port 52 a opened toward rearwardly downward, and rearwardlyupward at the rear end of the vehicle body 5. The exhaust duct 52 guidesexhaust gas (excess gas) ejected from the fan of the fuel cell 2 to theexhaust port 52 a and discharges it to the rear of the vehicle body 5.

The exhaust port 52 a is disposed higher than the exhaust face (backface), and preferably at the upper end part of the rear section of theexhaust duct 52. In other words, the upper edge part of the exhaust port52 a is disposed at a position higher than the exhaust port of the fuelcell 2. As a result of having the exhaust port 52 a disposed to behigher than the exhaust face (back face) of the fuel cell 2, the exhaustduct 52 guides a wet excess gas containing unreacted hydrogen gas to theexhaust port 52 a and securely discharge it from the vehicle body 5.

The fuel tank 15 is a high-pressure compressed hydrogen storage system.The fuel tank 15 includes a pressure vessel 55 made of carbon fiberreinforced plastic (CFRP), or being a composite vessel made from analuminum liner, a fuel filling joint 57 having a fuel filling port 56, afuel filling main valve 58, a fuel supply main valve 59 integrallyincluding a shut-off valve (not shown) and a regulator (not shown), anda secondary pressure reducing valve (not shown).

The pressure vessel 55 is a composite vessel made from an aluminum linerwhich stores hydrogen gas as fuel of the fuel cell 2. The fuel tank 15stores, for example, hydrogen gas of about 70 megapascal (MPa.) Thepressure vessel 55 includes a cylinder-shaped barrel part, and adome-shaped mirror plate provided on front and rear end faces of thebarrel part. The pressure vessel 55 is disposed in the center tunnelregion 35 with the central axis of the cylindrical barrel being alignedalong the front and rear direction of the vehicle body 5. The pressurevessel 55 is surrounded by a pair of upper frames 25, a pair of lowerframes 24, a lower bridge frame 28, and a guard frame 29, and isrobustly protected against load due to turning over or collision of theelectric vehicle 1.

The pressure vessel 55 is supported in the center tunnel region 35 by aclamp band 61 constructed between an upper frame 25 disposed at one sideof the vehicle body 5, for example, the upper frame 25 disposed at theright side of the vehicle body 5, and a lower frame 24 disposed atanother side of the vehicle body, for example, the lower frame 24disposed at the left side of the vehicle body 5. The pressure vessel 55is placed on a lower clamp band, for example, a lower half part of theclamp band 61 being constructed between the right side upper frame 25and an left side lower frame 24, and is clamped by the upper clamp band,for example, an upper half part of the clamp band 61 to be sandwiched.Note that the clamp band 61 may be constructed between the upper frame25 disposed at the left side of the vehicle body 5 and the lower frame24 disposed at the right side of the vehicle body 5.

The fuel filling joint 57 is disposed outside of the center tunnelregion 35, more specifically, rearwardly upward of the center tunnelregion 35, and at the front end part of the instrument mounting region36. The fuel filling joint 57 is disposed to be higher than or justabove the rechargeable battery 16. The fuel filling joint 57 is securedto the joint bracket 30f being constructed between the upper parts ofthe front protection frame 30 a and the center protection frame 30 b ofthe mounted-instrument protection frame 30. The fuel filling joint 57extends toward upward, and slightly leftward of the vehicle body 5 suchthat a facility side joint can be inserted from the upper side and leftside of the vehicle body at the time of fuel filling. The fuel fillingjoint 57 is covered and hidden by the fuel filling port lid 62 beingdisposed at the front end of the seat 13. The fuel filling port lid 62is supported to the seat 13 via a hinge mechanism (not shown), andopens/closes by being swung. The fuel filling joint 57 has a fuelfilling port 56 as an inlet for introducing high pressure gas ofhydrogen as a fuel into the fuel tank 15.

The fuel filling port 56 is disposed at a top part of the fuel fillingjoint 57. The fuel filling port 56 is oriented toward the upper left ofthe vehicle body 5. In filling the fuel tank 15 with fuel, the upward ofthe fuel filling port 56 is opened to the atmosphere in a state in whichthe fuel filling port lid 62 is opened. Thus, in charging high pressuregas, for example, hydrogen gas as fuel, into the fuel tank 15, even ifthe high pressure gas leaks, the leaked fuel diffuses toward the upwardof the electric vehicle 1 without residing therein.

A fuel filling main valve 58 and a fuel supply main valve 59 areintegrated and incorporated in a tank valve 63 provided on the top partof the rear-side mirror plate of the pressure vessel 55. The tank valve63 is disposed in a space surrounded by the guard frame 29. The fuelsupply main valve 59 includes a shut-off valve (not shown) and a primarypressure reducing valve (not shown). The fuel filling main valve 58 andthe shut-off valve of the fuel supply main valve 59 are an on-off valveusing an electromagnetic valve. The primary pressure reducing valve andthe secondary pressure reducing valve of the fuel supply main valve 59successively reduce and thereby adjust the pressure of the high pressurefuel gas from the pressure vessel 55.

The rechargeable battery 16 is a box-shaped lithium ion battery. Therechargeable battery 16 is disposed in the front end part of theinstrument mounting region 36 and between the rear half part of thepressure vessel 55, that is, the rear half part of the cylindricalbarrel and the rear-side mirror plate, and the front half part 13 a ofthe seat 13.

Note that, the electric vehicle 1 includes, besides the rechargeablebattery 16, a second rechargeable battery (not shown) supplying, forexample, 12V-based power as a power supply for meters (not shown) andlights (not shown). The second rechargeable battery is disposed aroundthe head pipe 21, for example, beside the right side of the head pipe21.

In the electric vehicle 1, even if hydrogen gas as fuel leaks from thefuel filling port 56, the hydrogen gas, which is lighter than air, movesup, thus diffusing to the outside of the electric vehicle 1 withoutresiding within the electric vehicle 1. Even if hydrogen gas as fuelleaks from the fuel filling main valve 58 or the fuel supply main valve59, the hydrogen gas moves toward the tire house region 37, thusdiffusing to the outside of the electric vehicle 1 without residingwithin the electric vehicle 1.

The power management apparatus 17 is disposed between the rechargeablebattery 16 and the fuel cell 2 in the instrument mounting region 36, andis secured to the frame 11. Note that the power management apparatus 17may be disposed along with the rechargeable battery 16 in a samewaterproof case.

By disposing the rechargeable battery 16, the power management apparatus17, and the fuel cell 2 in a manner as described above, it becomespossible to dispose apparatuses adjoining to each other in theelectrical connection to be closer to each other as much as possible,thus shortening the wiring length between the apparatuses, and reducingthe weight relating to the wiring.

The vehicle controller 19 is disposed around the head pipe 21 being arelatively high place in the electric vehicle 1, for example, beside theleft side of the head pipe 21 corresponding to the opposite side of thesecond rechargeable battery, which supplies 12 V-based power.

Next, a cooling structure of a power converter of the electric vehicle 1will be described in detail.

FIGS. 4 and 5 each are a perspective view of the cooling structure ofthe power converter of the electric vehicle according to the embodimentof the present invention.

FIG. 6 is a plan view of the cooling structure of the power converter ofthe electric vehicle according to the embodiment of the presentinvention.

FIG. 7 is a right side view of the cooling structure of the powerconverter of the electric vehicle according to the embodiment of thepresent invention.

FIG. 7 illustrates a state where the exterior 12 is detached.

As shown in FIGS. 4 to 7, a cooling structure 71 of a power converter 69of the electric vehicle 1 according to the present embodiment includesthe frame 11 extending in the longitudinal direction, the powerconverter 69 being long in the longitudinal direction along the frame11, the exterior 12 extending in the longitudinal direction to cover theframe 11 and the power converter 69.

The power converter 69 is a DC-DC converter, for example. The powerconverter 69 has an input connected to the fuel cell 2 and therechargeable battery 16. The power converter 69 has an output connectedto electric components such as meters (not illustrated) and lamps (notillustrated), and the second rechargeable battery. The power converter69 converts direct-current power supplied from the fuel cell 2 and therechargeable battery 16 into direct-current power of high voltage (e.g.48 volt system) to be supplied to the electric motor 3 or direct-currentpower of 12 volt system to be supplied to the electric components otherthan the electric motor 3 to output the direct-current power.

The power converter 69 is disposed on any one of sides of the fuel tank15, for example, on a right side thereof. The power converter 69 has alength similar to that of the pressure vessel 55 of the fuel tank 15,and extends in the longitudinal direction of the vehicle body 5 with itsfront and rear ends being substantially aligned with respective frontand rear ends of the pressure vessel 55. The front end of the powerconverter 69 is disposed behind the lower bridge frame 28 of the frame11. The rear end of the power converter 69 is disposed ahead a rear endof a valve protection frame 73. The valve protection frame 73 isprovided between inclined portions on a rear side of the right and leftlower frames 24 to surround the fuel filling main valve 58 and the fuelsupply main valve 59 (tank valve 63) of the fuel tank 15. The front endof the power converter 69 is fixed to the front-side inclined portion ofthe lower frames 24 with fasteners, for example, bolts (notillustrated). The rear end of the power converter 69 is fixed to therear-side inclined portion of the lower frames 24 with fasteners, forexample, bolts (not illustrated). The power converter 69 allows itsfront and rear ends to be fixed to the lower frames 24 to transmit itsheat the lower frames 24, thereby enabling heat dissipation, as well asto couple the front-side inclined portion and the rear-side inclinedportion of the lower frame 24 to each other for reinforcement.

The power converter 69 includes a case in the shape of an elongatedrectangular parallelepiped. The power converter 69 is disposed at aposition above the lowermost portion of lower frame 24. The powerconverter 69 has a left side face entering a space between the rightupper frame 25 and the right lower frame 24 in the frame 11, that is,the center tunnel region 35. The left side face of the power converter69 faces the pressure vessel 55. The power converter 69 has a right sideface facing an inner surface of the exterior 12. The power converter 69has a top face facing the right upper frame 25. The power converter 69has a bottom face facing the right lower frame 24.

The right side face of the power converter 69, that is, the face facingthe exterior 12 includes a plurality of heat radiation fins 75. The heatradiation fins 75 arrange vertically and extend in the longitudinaldirection. The heat radiation fins 75 also extend backward along thefoot board 31 of the exterior 12 at a slightly upward angle.

An electric power line 77 connected to the power converter 69, that is,the electric power line 77 connecting the power converter 69 and therechargeable battery 16 to each other is wired from the front end of thepower converter 69 while detouring in front of the lower bridge frame 28at the right side to the power converter 69. An electric power line (notillustrated) connecting the power converter 69 and the fuel cell 2 toeach other is attached to the rear end of the power converter 69. Theelectric power line connecting the power converter 69 and the fuel cell2 to each other is wired upward.

The exterior 12 includes the foot board 31, a foot board lower cover 81provided below the foot board 31, a lower leg shield cover 82 with whicha front face of the power converter 69 is covered, an undercover 83connected to a lower end of the lower leg shield cover 82 to cover thepower converter 69 together with a bottom portion of the frame 11, and arear lower fender cover 84 provided behind the undercover 83 to coverthe power converter 69.

The foot board 31 is connected to a lower end of each of the front framecover 42 and the frame cover 43, and has appropriate height and widthallowing a rider and a fellow passenger to place their feet thereon.

The foot board lower cover 81 extends back and forth along an outer edgeportion of the foot board 31.

The lower leg shield cover 82 is connected to a lower end of the frontleg shield cover 41 to cover a lower end of a front face of the vehiclebody 5. The lower leg shield cover 82 extends in a U-shape, as viewedfrom the front of the vehicle body 5, to cover the lower frame 24 andthe lower bridge frame 28 of the frame 11.

The undercover 83 cover the fuel tank 15, the right and left lowerframes 24, and the power converter 69 from below.

The rear lower fender cover 84 is provided below the frame cover 43 toconstitute a right and left pair of rear lower fender covers 84, and isdisposed at a front end of the tire housing region 37 to cover a frontend of the swing arm 9 supported by the pivot shaft 26 from the left andright sides to protect the front end of the swing arm 9.

The exterior 12 is provided with a recessed portion 85 below the seat13, in particular substantially immediately below a front end of theseat 13. The recessed portion 85 is provided in a part of the exterior12, for example, in the foot board 31 and the foot board lower cover 81,and recessed toward a central side of the vehicle body 5. The recessedportion 85 improves foot-grounding capability when a rider stops thevehicle or rides it.

The power converter 69 may be disposed on a left side of the fuel tank15. In this case, a right and left relationship among the frame 11, theexterior 12, and the power converter 69 is reversed.

FIG. 8 is a front view of the cooling structure of the power converterof the electric vehicle according to the embodiment of the presentinvention.

FIG. 9 is a rear view of the cooling structure of the power converter ofthe electric vehicle according to the embodiment of the presentinvention.

FIGS. 10 and 11 each are a sectional view of the cooling structure ofthe power converter of the electric vehicle according to the embodimentof the present invention.

FIG. 11 is a sectional view taken along the recessed portion 85, andFIG. 10 is a sectional view taken along a general portion other than therecessed portion 85.

As shown in FIGS. 8 to 11, the exterior 12 of the cooling structure 71according to the present embodiment extends in the longitudinaldirection of the electric vehicle 1 to cover the frame 11 and the powerconverter 69, and defines a cooling air path 87 between the powerconverter 69 to allow cooling air to flow through the cooling air path87. The cooling air path 87 extends along the longitudinal direction.

The cooling air path 87 is a space defined by the inner surface of theexterior 12, that is, by an inner surface of each of the lower legshield cover 82, the undercover 83, and an inner surface of the rearlower fender cover 84, and a right side face of the power converter 69.The cooling air path 87 extends in the longitudinal direction of thevehicle body 5 in the shape of a duct. The cooling air path 87 isdefined by the exterior 12 expanding toward the outside of the vehiclebody 5 with respect to the right side face of the planar power converter69, which is not limited. The cooling air path 87 may be defined by acombination of the power converter 69 having a right side face recessedtoward a central side of the vehicle body 5 or a fuel tank 15 side, anda flat exterior 12.

The exterior 12 includes an air induction port 88 provided at a frontend of the cooling air path 87 to allow travelling wind to flow into thecooling air path 87. The air induction port 88 is provided in the lowerleg shield cover 82, and is disposed in front of the power converter 69.The air induction port 88 is disposed at a side of the front wheel 6 asviewed from the front of the electric vehicle 1, and is opened towardthe front of the electric vehicle 1. The air induction port 88 is atriangular opening, as viewed from the front of the vehicle, extendingtoward a central side of the electric vehicle 1 so as to avoid the frontfork 46. The air induction port 88 includes a mesh filter 89. The meshfilter 89 prevents a foreign matter such as a leaf from entering thecooling air path 87. Behind the air induction port 88, the front end ofthe power converter 69 extends toward the air induction port 88 and isdisposed close to the air induction port 88. The front end of the powerconverter 69 guides travelling wind flowing through the air inductionport 88 to the cooling air path 87, which is a space between theexterior 12 and the power converter 69. The electric power line 77 isconnected to the front end of the power converter 69.

The exterior 12 includes an air exhaust port 91 provided at a rear endof the cooling air path 87 and facing the rear of the electric vehicle 1to allow air to flow out from the cooling air path 87. The air exhaustport 91 is provided in the rear lower fender cover 84. The air exhaustport 91 is disposed behind the power converter 69. The air exhaust port91 is disposed at a side of the rear wheel 8 as viewed from the rear ofthe electric vehicle 1, and is opened toward the back or rear of theelectric vehicle 1 to allow air in the cooling air path 87 to bedischarged by using a flow of air passing through the side of theelectric vehicle 1, that is, air flowing through the outside of theexterior 12, as the electric vehicle 1 travels. The air exhaust port 91avoids the swing arm 9 as viewed from the rear of the electric vehicle1. The heat radiation fins 75 are disposed in the air exhaust port 91 asviewed from the rear of the electric vehicle 1.

The power converter 69 extends in the longitudinal direction in thecooling air path 87. The power converter 69 includes the heat radiationfins 75 protruding toward the inner surface of the exterior 12. The heatradiation fins 75 may be molded integrally with the case of the powerconverter 69, or may be formed by thermally connecting a separatedcomponent to the case.

Some of the heat radiation fins 75, which are heat radiation fins 75 a,are closer to the inner surface of the exterior 12 than heat radiationfins 75 b at other portions. The heat radiation fins 75 a include a heatradiation fin 95 disposed at an uppermost portion, and a heat radiationfin 96 disposed at a lowermost portion.

That is, such the heat radiation fins 75 a are closer to the innersurface of the exterior 12 than the heat radiation fins 75 b at otherportions, and the heat radiation fins 75 b at the other portions arefarther from the inner surface of the exterior 12 than the heatradiation fins 75 a and have a larger gap. This gap between the heatradiation fins 75 b at the other portions and the exterior 12 is a partof the cooling air path 87 to serve as a duct guiding air to the heatradiation fins 75. The heat radiation fins 75 a are closer to the innersurface of the exterior 12 than the heat radiation fins 75 b at otherportions, and preferably are close to the extent of not being broughtinto contact with the inner surface to prevent travelling wind fromleaking to the outside of the cooling air path 87 through the gapbetween the exterior 12 and the heat radiation fins 75. An aspect ofallowing the heat radiation fins 75 a at same potions and the innersurface of the exterior 12 to close to each other may be achieved byallowing the heat radiation fins 75 a to protrude more than the heatradiation fins 75 b at those portions, or by allowing the heat radiationfins 75 to uniformly protrude while the exterior 12 is expanded to allowonly the heat radiation fins 75 a at same portions to be close to theexterior 12, and an aspect of a combination of both aspects above isalso available.

The foot board 31 of the exterior 12 is disposed closely to a top faceof the power converter 69. This reduces the gap between the exterior 12and the power converter 69 to further prevent travelling wind fromleaking.

The recessed portion 85 of the exterior 12 partially reduces across-sectional area of the cooling air path 87. The protruding lengthof each of the heat radiation fins 75 is reduced along the recessedportion 85. The recessed portion 85 allows the exterior 12 to be closeto a leading end of each of the heat radiation fins 75 to partiallyreduce a cross-sectional area of the cooling air path, therebyincreasing air velocity at the recessed portion to accelerate heatexchange at the heat radiation fins 75, and thus cooling performance ofthe power converter 69 is improved. The recessed portion 85 may extendto a side closer to the power converter 69 than a virtual lineconnecting leading ends of the heat radiation fins 75 at the front andrear of the recessed portion 85. In such manner, the heat radiation fins75 allow air flowing through the cooling air path 87 to be urged to flowinto a region where the protruding length of the heat radiation fins 75are reduced, thereby improving the cooling performance. That is, therecessed portion 85 of the exterior 12 simultaneously improvesfoot-grounding capability of a rider in a case where the electricvehicle 1 is stopped, and the cooling performance of the power converter69. A circuit generating large heat in the power converter 69 isdisposed near the recessed portion 85, the circuit also can beefficiently cooled.

The electric vehicle 1 according to the present embodiment allows someof the heat radiation fins 75 (75 a) to be disposed closer to the innersurface of the exterior 12 than the heat radiation fins 75 (75 b) atother portions, and thus the power converter 69 is efficiently cooled bycontrolling a flow direction of travelling wind to guide the travellingwind to the heat radiation fins 75 and to allow the travelling wind tosmoothly flow along the heat radiation fins 75.

Further, the electric vehicle 1 according to the present embodimentenables the exterior 12 and the power converter 69 to define the coolingair path 87 in the shape of a duct, and thus no extra component isneeded to cool the power converter 69, and cooling efficiency of thepower converter 69 can be improved while the number of components isreduced.

Further, the electric vehicle 1 according to the present embodimentallows some of the heat radiation fins 75, which are the heat radiationfins 75 a closer to the inner surface of the exterior 12 than the heatradiation fins 75 at other portions, to include the heat radiation fin95 disposed at the uppermost portion and the heat radiation fin 96disposed at the lowermost portion, and thus travelling wind is preventedfrom leaking from the cooling air path 87 so as to more reliably coolthe power converter 69 without reducing an air flow of travelling windin the cooling air path 87.

Further, the electric vehicle 1 according to the present embodimentincludes the recessed portion 85, and thus flow velocity is increased ata portion in the cooling air path 87 to increase cooling efficiency atthe portion, whereby the circuit with the large heating value in thepower converter 69, for example, is intensively cooled, and alsofoot-grounding capability of the electric vehicle 1 is improved.

Therefore, the electric vehicle 1 according to the present invention iscapable of efficiently and reliably cooling a power converter 69disposed inside the exterior 12.

What is claimed is:
 1. An electric vehicle comprising: a frame extendingin a longitudinal direction of the electric vehicle; a power converterbeing long in the longitudinal direction of the electric vehicle alongthe frame; and an exterior extending in the longitudinal direction ofthe electric vehicle to cover the frame and the power converter, theexterior defining a cooling air path between the power converter toallow cooling air to flow the cooling air path, wherein the powerconverter includes a plurality of heat radiation fins extending in thelongitudinal direction of the electric vehicle in the cooling air path,the heat radiation fins protruding toward an inner surface of theexterior, and some of the heat radiation fins are closer to the innersurface of the exterior than the other heat radiation fins.
 2. Theelectric vehicle according to claim 1, wherein the some of the heatradiation fins include a heat radiation fin disposed at an uppermostportion, and a heat radiation fin disposed at a lowermost portion. 3.The electric vehicle according to claim 1, wherein the exterior includesa recessed portion that partially reduces a cross-sectional area of thecooling air path, and each heat radiation fin has a protruding lengthreduced along the recessed portion.
 4. The electric vehicle according toclaim 2, wherein the exterior includes a recessed portion that partiallyreduces a cross-sectional area of the cooling air path, and each heatradiation fin has a protruding length reduced along the recessedportion.